The present invention relates to a method of maintaining a fastening member of a hook and loop fastener system in a storage position on an article. The invention further relates to apparatus for carrying out the method.
Various fastener systems have been employed on inexpensive or disposable articles such as diapers, including lengths of pressure-sensitive adhesive coated tape, snaps, and hook and loop fasteners. Due in part to the susceptibility of adhesive coated tape to contamination by e.g. talcum powder or baby oil, diapers equipped with hook and loop fastener systems now occupy a growing share of the market.
Different types of hook and loop fastener systems are known. In this respect, reference is made to EP-A-0 491 347, EP-A-0 324 578 and EP-A-0 276 970. Common to these systems is the provision of a fastening tab normally attached to a first waist portion of a diaper, the fastening tab being provided with a region of hook material, and a receiving zone normally on a second waist portion of the diaper, the receiving zone having a plurality of loops to be engaged by the hooks. The fastening tab is commonly a flexible elongate rectangular strip of polymeric material, a first end portion of which is attached to the diaper. The region of hook material is located at a distal end portion of the tab and this distal end portion of the tab extends beyond the edge of the diaper to allow the first waist portion of the diaper to be placed around a wearer and secured to the second waist portion to thereby maintain the diaper in place on the wearer.
A disposable diaper generally comprises a liquid impermeable backsheet, a liquid permeable topsheet, and an absorbent core sandwiched between the topsheet and backsheet. For improved fit and comfort, disposable diapers may also have elasticated leg cuffs and elasticated waist portions. The production process for disposable diapers is highly automated, with constituent materials being supplied to the production line and finished products leaving the production line already packaged for delivery to the consumer. As with all production line processes, faulty batches and stoppages must be avoided.
Hook and loop fastener systems are applied to partially completed diapers as the diapers proceed along the production line. In order to prevent the fastening tabs of the hook and loop fastener system from fouling machinery as the diapers proceed along the production line, it is important that the tabs be maintained in a storage position in which the distal end portion of the tab is folded over the first end portion to thereby preferably contact the topsheet of the diaper. This storage position should be maintained throughout the passage of the diaper along the production line so that the diaper is folded and packaged with the tabs in the storage position. In this manner, when the consumer opens the package, he/she is presented with neatly folded diapers with no visibly protruding tabs.
Although many diapers nowadays have topsheets made from nonwoven material which, to a certain extent, presents loops with which the hooks of the fastening tabs can engage when the tab is folded over to its stored position, the strength of the engagement has sometimes been found to be insufficient to guarantee that the tabs will maintain this storage position during the passage of the diaper along the production line. As a consequence, due to their resilience, the tabs may spring open and snag in machinery of the production line, thereby possibly resulting in production stoppage and/or waste due to the occurrence of faulty products.
In the above-mentioned EP-A-0 324 578, this problem is partially solved by providing a tab with a layer of pressure sensitive adhesive along its central portion such that the central portion of the tab can adhere to the portion of the tab which is permanently attached to the diaper when the tab is in a storage position.
A further conceivable solution to this problem could be to provide the topsheet of the diaper with a patch of loop material adjacent the first end portion of the tab such that the distal end portion of the tab carrying the hooks could engage the patch of loop material in the storage position. Such a solution would however imply higher costs due to the need for additional loop material.
It is therefore an object of the present invention to provide an alternative method of maintaining a fastening tab or member of a hook and loop fastener system in a storage position, which method avoids the drawbacks associated with other methods.
Since the claimed method ensures improved engagement between the surface of the article and the hook members, existing components of the diaper can be utilized for this purpose without the need for additional means such as adhesive or extra loop material.
It is a further object to provide apparatus for carrying out the method according to the invention.
It is yet another object of the invention to provide a diaper which displays improved properties with regard to maintenance of the storage position of its fastening members.
Preferred embodiments of the method and apparatus are detailed in the respective dependent claims.